1. Field of the Invention
This disclosure generally relates to received signal strength indicators and more particularly to systems and methods for received signal strength indicators for signals having small amplitudes.
2. Discussion of the Related Art
A received signal strength indicator (RSSI) is a measurement of the power present in a received signal of a communication receiver. In practice, the received signal is usually an AC (alternating current) signal. To detect the power present in an AC signal, a rectification circuit is needed. Rectification is the conversion of an AC signal into a DC (direct current) signal. As is known, the power of a DC signal can be conveniently measured. In prior art systems, rectification is usually accomplished by using a diode circuit. However, a diode has an inherent non-zero threshold voltage (which is typically 0.6V) and therefore a diode circuit cannot rectify a small AC signal whose amplitude is below its threshold voltage.